Why do I always become so sentimental at night?

That sometimes happens to me too. During the day, you don't have the time of mind to really think about how lonely you are, about your life. And at night, just before you fall asleep, you have time to really reflect on your day and think about what happened. You pick out the little details that bother you, and then that's when you wish it could be mended. I know it sounds childish, but getting a big stuffed animal might help :) At least you'd have somebody to hug. If you have a boyfriend, you could always ask him to come over and comfort you. You could also start a journal. It helps to write down what's really bothering you. Hope I helped :)